Gear-pump.



l- T. ZOTTOLII.

GEAR PUMP.

APPLICATION FILED 6.8. 1917- INVENTY Pat-entail Nov. 5,1918,

' Gear-Pumps,

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GEAR-PUMP.

as es.

Application filed August 8, 1913". Serial No. 185,160. r i i To all whomit may concern:

Be itknown that I, JOSEPH T. ZoT'roLI, a citizenofthe United States,residing at Bos ton, in the county of Suffolk and Commonwealth ofMassachusetts, have invented a certain new and useful Improvement in ofwhich the following is a specification, the accompanying drawings.

The invention relates to a new and useful improvement in gear pumps.Itis especially intended for application to use in a device forautomatically pumping out water from a leaky boat or for pumping waterfrom the water compartments of a submarine when it is desired to removethe water from the box or casing being water compartments to permit theboat to rise to the surface.

One object of the invention is to pump of the above mentioned characterwhich is connected with a hose or pipe leading from the boat orcompartment which is to be pumped out, the hose being long enough sothat while one end of it opens into the compartment which is to bepumped out, the pumpis connected with the other end of the hose and maybe passed overboard, and the force of the water while the boat is inmotion and the pump is being dragged in the water, will actuate the pumpautomatically.

The invention will be fully understood from the following description,taken in connection with the accompanying drawings,

provide a and the novel features thereof will be pointed out and clearlydefined inthe claims at the close of this specification.

In the drawings,Figure 1 is a vertical sec tion of a device embodyingthe invention.

Fig. 2 is a view of a portion of the parts shown in. Fig. 1, the upperportion of the partly broken away and showing the gears in the positionthey will be after they have revolved part way around from the positionshown in Fig. 1.

Fig. 1.

Fig. 4: is a side view of a boat in the water and equipped with theapparatus, showing the gear pump submerged in the water outside of theboat, and the hose leading therefrom over the side of the boat andextending down into the water which is being pumped out of the bottom ofthe boat. Fig. 5 is a plan View of a submarine, showing a modified formofcasing for the gears, for a submarine.

Specification of Letters Patent.

reference being had therein to 1g. 3 1s a vertical section on line 3-3of Patented Nova 5, 1918.;

Fig. 6 is a detail view showing on a larger scale the pump shownin Fig.5.

Referring-now to the drawings, A and B respectively denote two gearswhich are exactly alike and which mesh with each other, each beingjournaled in hearings in the two end walls 1, 2, ofthe gear caseor box.In the form shown in the drawings, each gear 1s formed with acylindrical projection 3 at each end which serves as a journal androtatesin a bearing in the end wall of the case. Any suitable form ofjournal, however, may be employed. llt is desirable that the journalshall fit as closely as possible in the bearmg to allow easy rotation,yet be packed in such manner as to prevent, as far as possible, leakageof water through the bearings.

The end walls 1, 2 of the casing preferably have a flaring top and amore 0011- tracted lower end as shown in Figs. 1 and 2, the said casingbeing open at the bottom and at the top.

Each of said gears is formed with teeth 4, preferably four in number,the periphery of each tooth being convex in cross section and betweenthe teeth are depressions or pockets 5 which are concave in crosssection, that is, both sections being taken transversely of the axis ofthe gear. The radius of curvature of the periphery of the be the same asthe radius of the pocket, but the pocket should be of a greater lengthof arc than the arc of the tooth. The preferable proportion is to makethe arc of the curve. of the pocket twice that of the tooth. if fourteeth are employed as shown in the drawings, the tooth should have anarc of about 90, and the pocket should have an arc of about 180.

The two gears should be so mounted in re lation to each other that theteeth of each will successively and alternately bottom in the pockets ofthe other.

A hood 7 is provided for the gears, said hoodextending the full lengthof the casing, that is, the full distance between the two end walls 1, 2and having two wing portions 8, 9,

which respectively extend down over the upl teeth should preferably stemis adapted to be connected with a hose 12 whose other end will open intothe inte rior of the boat 13 or compartment which is to be pumped out.

The lower end of each wing 8, 9, is concaved on a curve whose radius isthe distance from the high point of each tooth of thegear tothe centerof the gear.

Said hood is so adjusted with relation to the gears that as thegearsrotate, the high point of each tooth will have a grazing contactwith the concave vface of the wing 8 or 9 asthecase may be, from thetime that the high point of the tooth reaches the inner edge of thewing, until it .passes oil the outer edge of the wing. Also, thelengthof the are from, the inner edge to the outer edge of each wing,for instance, from the point 14:

through the hood to the passages through the pockets of device is thrownoverboard, and trolled at during the to the point 15, willbe greaterthan the distance from the high point 16 of onetooth to thehigh point 16of the next tooth, so that the high point 16 of one tooth willnot rideof? ofth'e outer edge 15 of the wing before the high point 16 of thenext following tooth begins to engage the inner edge 14: of thewing,-.in order that thereshall be, at no time, an open communicationfrom the passage 11 18 and 21 which lie between the gears-and the sidewalls 19 and'22 of the casing. Thus the water which passes down. throughthe passage 11 can escape only as it is carried out the gears. When thethe end of the hose 12 with the boat, the easing and its attachedpartswill be dragged head first, thatis, the bell shaped open end willbe toward the front,'so that the water, travelof theboat, will pass intothe casing from the larger frontend 20 and out through the contractedrear end 17 It is to be notedthat viewedin cross section as shown inFig. 3, the gears are of'sufficient length to extend the full length ofthe space between the two end walls 1 and 2, but

viewed at rightv angles to Fig. 3, as in Figs. 1 and 2, there are spaces.18 and 21 between the walls 19,22 of the casing, and the'lower edges 1523 of'the wings 8, 9, thus allowing the water to freely pass throughthese spaces 18, 21 from the larger end of the casingto the smaller endofthe casing. As the water rushes through these spaces, or perhaps morecorrectly, as the casing is dragged throughthe water, the water Wlllenter the open pockets on the lower side of the wings and the pressurewill be against the'side of each pocket which is most directly opposed.andthus cause the. gears to rotate in opposite directions to each otheras indicated-by thearrows. Theteeth as theyface the hood will rotatetoward each other, and the teethtoward the exit end will'rotate awayfrom each other.

As'the'gears thus rotate, each tooth 21S'1t moves past the open lowerend of the passage 11 in the hood, will cause a suction down through thepassage 11, carrying a pocket full of air, as for instance indicated bythe space in the inclosed pocket 5 of gear A shown in Figs. 1 and 2,which will be expelled as soon as the gear has rotated far enough so asto open said pocket down below the lower edge 15 of the wing 8. Asimilar action takes place by the rotation of the gear B, a pocket fullbeing emptied alternately by the two gear wheels, and each tooth insuccession discharges a pocket full. If there is any water in the boat,and if the end of the hose 12 opens into it while the gear pump istrolled in the water outside, as shown in Fig. t, the suction will drawthe water out of the boat and down through the hood and the gears,whence it will be discharged.

On the upward movement of each tooth there will be a drawing in of asmall quantity of water from the outside body of water in which the pumpis submerged, but the largest quantity of water drawn in each time willbe the amount which can be contained in the small inclosed space 25formed between two teeth of the two gears on their upward stroke. Thisinclosed space is very much smaller than the full size of the pocket,and as the amount of water carried out by each pocket is an entirepocket full, the water will be carried out'much faster than it can betaken in, thus the water will be gradually drawn out of the boat orcompartment which is being pumped out.

In the equipment which I especially intend for a submarine, the pump,instead of being connected with a long hose, and thrown overboard asalready described, is permanently attached tothe interior ofthesubmarine as shown by the casing 30 in Figs. 5 and 6 and is formed withtwo pipe branches 31, 82, which pass out through the side of the boat,the branch 31 communicating with the entrance end of the casing which isheaded in the direction that the boat goes, and the branch 32communicating with the rear end of the casing. These two branch pipeshave open outer ends 33, 34:, respectively, and as the vessel travelsthrough the water in the direction indicated by the arrow, the waterwill enter, the casing through branch 31 and will enter the pocketsoutside of the hood 35 androtate the-gears, thereby causing suctionthrough the pipe '36 from the interior of the water compartment 37 inthe manner already described with reference to the first form ofapparatus.

What I claim is v 1. In a gear pump, two intermeshing gears constitutingpumping elements, a casing in which said gears arejournaled, a hoodwhich extends lengthwise of the gears in position to permit water topass outside of it through the casing and is formed with two raeanaeconcave portions which respectively cooperate with said two gears, andwhich are so located and are concaved on such a radius with relation tothe diameter of the gears that during the rotation of the gears, eachtooth will form a grazing contact with one of the concave surfaces ofsaid hood during its travel, the length of the arc of the concavesurface of the hood being greater than the distance between two adjacentteeth, whereby, as the gear rotates, one tooth will not pass 0d of theconcave portion of the hood until the next following tooth comes intocontact with said concave surface of the hood.

2. In a gear gears constituting pumping elements, a casing in which saidgears are journaled, a hood which extends lengthwise of the gears inposition to permit water to pass outside of it through the casing and isformed with two concave portions which respectively 00- operate withsaid two gears and which are so located and are concaved on such aradius with relation to the diameter of the gears that during therotation of the gears, each tooth will form a grazing contact with oneof the concave surfaces of said hood during its travel, the length ofthe arc of the concave surface of-the hood being greater than thedistance between two adjacent teeth, whereby, as the gear rotates, onetooth will not pass ofi of the concave portion of the hood until thenext following tooth comes into contact with said concave surface of thehood, said hood being formed with a stem having an aperture extendinglengthwise therethrough from the concave end of the hood.

3. In a gear pump, two intermeshing gears constituting pumping elements,a casing in which said gears are journaled, a hood which extendslengthwise of the gears in position to permit water to pass outside ofit through the casing and is formed with two concave portions whichrespectively cooperate with said two gears and which are so located andare concaved on such a radius with relation to the diameter of the gearsthat during the rotation of the gears, each tooth will form a grazingcontact with one of the concave surfaces of said hood during its travel,the length of the are of the concave surface of the hood being greaterthan the distance between two adjacent teeth, whereby, as the gearrotates, one tooth will not pass off of the concave portion of the hooduntil the next following tooth comes into contact with said concavesurface of the hood, said hood being formed with a stem having anaperture extending lengthwise therethrough from the concave end of thehood, the casing being open at each end and having means which close theends of the pockets between the teeth of the pump, two intermeshinggears, and having open passages from one end to the other of the casingbetween the side wallsof the casing and the outer sides of said gears.

In a gear pump, two similar cooperating gears each having teethwhoseouter surface is convex,viewed transversely of the axis of thegear, the spaces between the teeth each being in theform of a groovepocket which is concave viewed transversely of the axisof the gear, theradius of curvature of the end of each tooth being the same length asthe radius of curvature of each concave pocket, in combination with agear case having two opposite walls in which said gears are journaled,and which close the entrance to the ends of the groove pockets in saidgears, a hood within said casing having two opposite wing portions whichare concaved on their inner ends, one of which wings spreads over aportion of one of said gears for the full length of said gear, and theother of which spreads over a portion of the other of said gears for thefull length there of, the said spreading portion of each of said wingsbeing concave in a direction transversely of the axis of the respectivegears on a curve whose radius is equal to the radius of the gear, thelength of the arc of the curve being somewhat greater than the distancebetween the highest points of two adjacent teeth, said hood being soadjusted with relation to said gears that in the rotation of the gears,the high point of each tooth will havea grazing contact with the concaveface of one of said wings, said hood being formed with an apertureextending from the inner end thereof to the outer end thereof.

5. In a gear pump, two cooperating gears each formed with teeth whichare convexly curved on their outer periphery transversely of the axis ofthe gear, concavely curved pockets between the teeth, said pockets beingconcaved transversely of the axis of the gear, the curves of the teethhaving the same radius as the curves of the pockets, the gears beingmounted in such manner that the teeth of one are adapted to intermeshwith the teeth of the other, and to be bottomed in the pockets of theopposing gear, a casing or box in which said gears are journaled, saidbox or casing having an open end, the casing having portions which closethe ends of the pockets, a hood which extends lengthwise of the gears,said hood being formed with two concaved or recessed portions whichrespectively cooperate with said two gears and which are so located andconcaved on such a radius with relation to the diameter of the gears,that, during the rotation of the gears, the high point of each toothwill form a grazing contact with one of the concave surfaces of saidhood during its travel, the length of the travel of each lllti teeth 1pv efthe ediipe lf'afiing "e'n'cave "surface off t helhqd, beihgf'gf'eziter th'anthe distance between 'thehigltpoints (if two adjacent teeth,whereby, es the gear rotates, the high phiiifiefiohe" tbbtlliwill notpass Off Of the eoheave' fpojritibn of the hood until :the next f 11ovvi11;g jtbbth cenies ihto 'jcohtact with Said fidncziyeisflffalce, 0f"the V hood, the said hbed'beifig 'fo'nhe'd" with ahollow stem hav- 1 0ifig an :t'p'erture which extends entirely thrhg'h the same from'themiter end to the inner end Of thehobdhhdbioenLs'ihto the interior'of t11e'h0(jd, 1f01"1niiig a pace which opens in'to'eaehpoekelt ofth'e gearssuccessi vely during their rotation, end a tubular connection with 'saidetem which is adapted tofbe connected'with the'intelior Of a boat.

In testimony whereof I 'effix my signature.

JOSEPH T. ZOTTOLI.

